Portable lift assembly

ABSTRACT

A portable lift assembly includes a rigid outer frame including a plurality of integrally mated support members configured to define a generally rectangular shape. A rigid inner frame including a plurality of integrally mated support members and having an outer perimeter is spaced inwardly from an inner perimeter of the outer frame. The assembly includes a mechanism for selectively elevating the inner frame along a vertical plane. The assembly further includes a mechanism for supporting at least one drywall panel on top of the inner frame wherein the drywall panel can be effectively elevated between alternate heights during operating conditions while the operator&#39;s hands remain freely disengaged from the drywall panel.

CROSS REFERENCE TO RELATED APPLICATIONS

Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not Applicable.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates to elevating apparatuses and, more particularly, to a portable lift assembly for lifting construction materials at a job site.

2. Prior Art

It is frequently necessary to lift workers or materials, particularly drywall, from the ground to an elevated position on construction sites, or to provide a safe work platform at desired elevation for various operations such as tightening of bolts or painting. Various lifting or elevating apparatuses have been developed and used. One common problem with the known arrangements is that the work platform, as it is lifted to an elevated position, is unstable and liable to swing due to winds, making the workers feel insecure and preventing them from doing desired works.

The work platform can be supported stably against unwanted wobbling movements by a rugged and heavy mechanism for lifting the platform or an additional mechanism for reinforcing the platform. However, these mechanisms are complex in construction, result in an additional cost, and cannot be transported easily. There is known a manual support arrangement in which a plurality of ropes are attached to an elongated ladder-like mechanism supporting thereon a work platform and manually pulled in opposite directions to render the platform stable against wobbling motions. Although the ladder-like platform supporting mechanism is relatively lightweight and thin in construction, several workers are required just for pulling and gripping the ropes. As a result, the known manual support apparatus has failed to find widespread general use.

Accordingly, a need remains for a lift assembly that can be easily transported to a job site and provides a stable platform for elevating materials. The present invention satisfies such a need by providing a portable lift assembly that allows a worker to raise, and then hold in place, drywall and other building materials. Such an invention would be especially helpful to drywall contractors because it would enable one person to install the drywall, saving a substantial amount of time and expense.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing background, it is therefore an object of the present invention to provide an apparatus for lifting construction materials. These and other objects, features, and advantages of the invention are provided by a portable lift assembly for assisting an operator to elevate drywall paneling towards a ceiling during installation procedures.

The lift assembly includes a rigid outer frame including a plurality of integrally mated support members configured to define a generally rectangular shape. The support members have substantially linear shapes and are formed from tubular steel. A rigid inner frame including a plurality of integrally mated support members and having an outer perimeter is spaced inwardly from an inner perimeter of the outer frame. The inner frame is telescopically positioned within the inner perimeter of the outer frame and along a substantially vertical plane such that the inner frame can be selectively biased between raised and lowered positions while the outer frame remains at a fixed ground position.

The assembly includes a mechanism for selectively elevating the inner frame along a vertical plane wherein the inner frame remains spaced inwardly from the outer frame such that the inner frame can be slidably guided along the vertical plane without directly contacting the outer frame. The assembly further includes a mechanism for supporting at least one drywall panel on top of the inner frame wherein the drywall panel can be effectively elevated between alternate heights during operating conditions while the operator's hands remain freely disengaged from the drywall panel.

Selected ones of the inner frame support members and selected ones of the outer frame support members are vertically oriented substantially parallel to the vertical plane and symmetrically spaced at opposing corners of the outer and inner frames respectively. Other ones of the support members are horizontally oriented and medially secured to the selected support members such that the other support members become vertically aligned along a longitudinal length of the selected inner frame and outer frame support members respectively.

The elevating mechanism preferably includes a manually-operable jack including a rotatable winch and oppositely positioned base and top surfaces. The base surface may be medially positioned on corresponding ones of the outer frame support members. The top surface may be medially engaged beneath corresponding ones of the inner frame support members such that opposing lift forces will cause the inner frame to be elevated when the operator adapts the jack between retracted and extended positions.

The elevating mechanism further preferably includes at least one rigid guide bracket having a linear central portion and an integrally coupled arcuate end portion slidably engageable with the inner frame. The guide bracket may further have an opposite end portion mated with the outer frame such that the guide bracket may be maintained at a static position while the inner frame is elevated toward the ceiling.

The drywall panel supporting mechanism preferably includes a substantially rectangular platform sized and shaped for being positioned on an upper end portion of the inner frame. The platform preferably has a substantially planar top surface oriented along the horizontal plane such that the drywall panel may be effectively maintained at equilibrium during transit.

A plurality of U-shaped brackets preferably are positioned about the inner frame and spaced along opposite sides thereof such that the brackets become situated subjacent the platform. Each U-shaped bracket preferably includes outwardly extending flange portions for threadably receiving fasteners therethrough such that the platform and the inner frame become securely coupled.

The outer frame further preferably includes a plurality of elongated rails connected thereto wherein selected ones of the rails are perpendicularly oriented along traversing planes and vertically aligned along the selected outer frame support members for providing additional stability during operating conditions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective view showing a portable lift assembly, in accordance with the present invention;

FIG. 2 is a perspective view showing the rigid outer frame of the present invention;

FIG. 3 is a perspective view of the inner frame of the present invention;

FIG. 4 is a cross-sectional view of the supporting mechanism, taken along line 4-4;

FIG. 5 is a cross-sectional view of the U-shaped brackets situated subjacent to the platform, taken along line 5-5; and

FIG. 6 is a cross-sectional view of the guide bracket engaging the inner frame.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, this embodiment is provided so that this application will be thorough and complete, and will fully convey the true scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the figures.

The apparatus of this invention is referred to generally in FIGS. 1-6 by the reference numeral 10 and is intended to provide a portable lift assembly. It should be understood that the apparatus 10 may be used to lift many different types of materials and objects for many different applications and should not be limited to only drywall construction.

Initially referring to FIG. 1, the lift assembly 10 includes a rigid outer frame 20 including a plurality of integrally mated support members 21 configured to define a generally rectangular shape. The support members 21 have substantially linear shapes and are formed from tubular steel. Of course, such support members 21 may also be formed from aluminum, stainless steel or other durable metal as well known in the industry. A rigid inner frame 30 including a plurality of integrally mated support members 31 and having an outer perimeter is spaced inwardly from an inner perimeter of the outer frame 20.

The inner frame 30 is telescopically positioned within the inner perimeter of the outer frame 20 and along a substantially vertical plane such that the inner frame 30 can be selectively biased between raised and lowered positions while the outer frame 20 remains at a fixed ground position. The outer frame 20 and inner frame 30 resemble conventional scaffolding commonly used in the construction industry, and operate on the same principle.

Still referring to FIG. 1, the lift assembly 10 includes a mechanism 40 for selectively elevating the inner frame 30 along a vertical plane wherein the inner frame 30 remains spaced inwardly from the outer frame 20 such that the inner frame 30 can be slidably guided along the vertical plane without directly contacting the outer frame 20. The lift assembly 10 further includes a mechanism 50 for supporting at least one drywall panel on top of the inner frame 30 wherein the drywall panel can be effectively elevated between alternate heights during operating conditions while the operator's hands remain freely disengaged from the drywall panel. Because drywall is easily damaged if dropped or mishandled, the lift assembly 10 reduces a contractor's costs by reducing the amount of handling, and thus, damage. Costs are further saved because workers do not have to lift the drywall by themselves, eliminating back strain and the resulting workers compensation claims.

Referring to FIGS. 2 and 3, selected ones of the inner frame support member 31A and selected ones of the outer frame support members 21A are vertically oriented substantially parallel to the vertical plane and symmetrically spaced at opposing corners 22, 32 of the outer 20 and inner 30 frames respectively. Other ones of the support members 21B, 31B are horizontally oriented and medially secured to the selected support members 21A, 31A such that the other support members 21B, 31B become vertically aligned along a longitudinal length of the selected inner frame 31A and outer frame 21A support members respectively.

Referring back to FIG. 1, the elevating mechanism 40 preferably includes a manually-operable jack 41 including a rotatable winch 42 and oppositely positioned base 43 and top 44 surfaces. The base surface 43 is medially positioned on corresponding ones of the outer frame support members 21. The top surface 44 is medially engaged beneath corresponding ones of the inner frame support members 31 such that opposing lift forces will cause the inner frame 30 to be elevated when the operator adapts the jack 41 between retracted and extended positions. The jack 41 is preferably similar to a standard automobile jack as is well known in the industry. Of course, a standard screw jack may also be used, as is also well known in the industry.

Referring to FIG. 6, the elevating mechanism 40 further preferably includes at least one rigid guide bracket 45 having a linear central portion and an integrally coupled arcuate end portion 46 slidably engageable with the inner frame 20. The guide bracket 45 may further have an opposite end portion 47 mated with the outer frame 20 such that the guide bracket 45 may be maintained at a static position while the inner frame 30 is elevated toward the ceiling.

Referring to FIGS. 1 and 4, the drywall panel supporting mechanism 50 preferably includes a substantially rectangular platform 51 sized and shaped for being positioned on an upper end portion 35 of the inner frame 30. The platform 51 may have a substantially planar top surface 52 oriented along the horizontal plane such that the drywall panel can be effectively maintained at equilibrium during transit.

Referring to FIG. 5, a plurality of U-shaped brackets 60 are preferably positioned about the inner frame 30 and spaced along opposite sides thereof such that the brackets 60 become situated subjacent the platform 51. Each U-shaped bracket 60 preferably includes outwardly extending flange portions 61 for threadably receiving fasteners 62 therethrough such that the platform 51 and the inner frame 30 become securely coupled. The U-shaped brackets 60 provide stability for the platform 51 so that loads positioned thereon are less likely to shift during operating conditions

The outer frame 20 further preferably includes a plurality of elongated rails 22 connected thereto wherein selected ones of the rails 22 are perpendicularly oriented along traversing planes and vertically aligned along the selected outer frame support members 21 for providing additional stability during operating conditions.

The lift assembly 10 provides a safe and easy method of raising drywall to a desired height and then holding it there while it is being secured to ceiling joists or wall studs. Such a lift assembly is light weight, reasonably priced, and offers an attractive cost saving alternative to renting a wheeled, gas-powered lift platform. The lift assembly 10 increases the level of safety on a job because workers would be less likely to attempt to lift and maneuver drywall panels themselves.

While the invention has been described with respect to a certain specific embodiment, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

In particular, with respect to the above description, it is to be realized that the optimum dimensional relationships for the parts of the present invention may include variations in size, materials, shape, form, function and manner of operation. The assembly and use of the present invention are deemed readily apparent and obvious to one skilled in the art. 

1. A portable lift assembly for assisting an operator to elevate drywall paneling towards a ceiling during installation procedures, said lift assembly comprising: a rigid outer frame including a plurality of integrally mated support members configured to define a generally rectangular shape; a rigid inner frame including a plurality of integrally mated support members and being telescopically positional within an inner perimeter of said outer frame and along a substantially vertical plane such that said inner frame can be selectively biased between raised and lowered positions while said outer frame remains at a fixed ground position; means for selectively elevating said inner frame along a vertical plane wherein said inner frame remains spaced inwardly from said outer frame such that said inner frame can be slidably guided along the vertical plane without directly contacting said outer frame; and means for supporting at least one drywall panel on top of said inner frame wherein the drywall panel can be effectively elevated between alternate heights during operating conditions while the operator's hands remain freely disengaged from the drywall panel.
 2. The lift assembly of claim 1, wherein selected ones of said inner frame support member and said selected ones of said outer frame support members are vertically oriented substantially parallel to the vertical plane and symmetrically spaced at opposing corners of said outer and inner frames respectively, other ones of said support members being horizontally oriented and medially secured to said selected support members such that said other support members become vertically aligned along a longitudinal length of said selected inner frame and outer frame support members respectively.
 3. The lift assembly of claim 2, wherein said elevating means comprises: a manually-operable jack including a rotatable winch and oppositely positioned base and top surfaces, said base surface being medially positioned on corresponding ones of said outer frame support members, said top surface being medially engaged beneath corresponding ones of said inner frame support members such that opposing lift forces will cause said inner frame to elevated when the operator adapts said jack between retracted and extended positions.
 1. The lift assembly of claim 1, wherein said elevating means further comprises: at least one rigid guide bracket having a linear central portion and an integrally coupled arcuate end portion slidably engageable with said inner frame, said guide bracket further having an opposite end portion mated with said outer frame such that said guide bracket can be maintained at a static position while said inner frame is elevated toward the ceiling.
 2. The lift assembly of claim 1, wherein said drywall panel supporting means comprises: a substantially rectangular platform sized and shaped for being positioned on an upper end portion of said inner frame, said platform having a substantially planar top surface oriented along the horizontal plane such that the drywall panel can be effectively maintained at equilibrium during transit; and a plurality of U-shaped brackets positioned about said inner frame and spaced along opposite sides thereof such that said brackets become situated subjacent said platform, each said U-shaped bracket including outwardly extending flange portions for threadably receiving fasteners therethrough such that said platform and said inner frame become securely coupled.
 3. The lift assembly of claim 2, wherein said outer frame further comprises: a plurality of elongated rails connected thereto wherein selected ones of said rails are perpendicularly oriented along traversing planes and vertically aligned along said selected outer frame support members for providing additional stability during operating conditions.
 4. A portable lift assembly for assisting an operator to elevate drywall paneling towards a ceiling during installation procedures, said lift assembly comprising: a rigid outer frame including a plurality of integrally mated support members configured to define a generally rectangular shape, said support members having substantially linear shapes and being formed from tubular steel; a rigid inner frame including a plurality of integrally mated support members and being telescopically positional within an inner perimeter of said outer frame and along a substantially vertical plane such that said inner frame can be selectively biased between raised and lowered positions while said outer frame remains at a fixed ground position; means for selectively elevating said inner frame along a vertical plane wherein said inner frame remains spaced inwardly from said outer frame such that said inner frame can be slidably guided along the vertical plane without directly contacting said outer frame; and means for supporting at least one drywall panel on top of said inner frame wherein the drywall panel can be effectively elevated between alternate heights during operating conditions while the operator's hands remain freely disengaged from the drywall panel.
 5. The lift assembly of claim 7, wherein selected ones of said inner frame support member and said selected ones of said outer frame support members are vertically oriented substantially parallel to the vertical plane and symmetrically spaced at opposing corners of said outer and inner frames respectively, other ones of said support members being horizontally oriented and medially secured to said selected support members such that said other support members become vertically aligned along a longitudinal length of said selected inner frame and outer frame support members respectively.
 6. The lift assembly of claim 8, wherein said elevating means comprises: a manually-operable jack including a rotatable winch and oppositely positioned base and top surfaces, said base surface being medially positioned on corresponding ones of said outer frame support members, said top surface being medially engaged beneath corresponding ones of said inner frame support members such that opposing lift forces will cause said inner frame to elevated when the operator adapts said jack between retracted and extended positions.
 7. The lift assembly of claim 7, wherein said elevating means further comprises: at least one rigid guide bracket having a linear central portion and an integrally coupled arcuate end portion slidably engageable with said inner frame, said guide bracket further having an opposite end portion mated with said outer frame such that said guide bracket can be maintained at a static position while said inner frame is elevated toward the ceiling.
 8. The lift assembly of claim 7, wherein said drywall panel supporting means comprises: a substantially rectangular platform sized and shaped for being positioned on an upper end portion of said inner frame, said platform having a substantially planar top surface oriented along the horizontal plane such that the drywall panel can be effectively maintained at equilibrium during transit; and a plurality of U-shaped brackets positioned about said inner frame and spaced along opposite sides thereof such that said brackets become situated subjacent said platform, each said U-shaped bracket including outwardly extending flange portions for threadably receiving fasteners therethrough such that said platform and said inner frame become securely coupled.
 9. The lift assembly of claim 8, wherein said outer frame further comprises: a plurality of elongated rails connected thereto wherein selected ones of said rails are perpendicularly oriented along traversing planes and vertically aligned along said selected outer frame support members for providing additional stability during operating conditions.
 10. A portable lift assembly for assisting an operator to elevate drywall paneling towards a ceiling during installation procedures, said lift assembly comprising: a rigid outer frame including a plurality of integrally mated support members configured to define a generally rectangular shape, said support members having substantially linear shapes and being formed from tubular steel; a rigid inner frame including a plurality of integrally mated support members and having an outer perimeter spaced inwardly from an inner perimeter of said outer frame, said inner frame being telescopically positioned within the inner perimeter of said outer frame and along a substantially vertical plane such that said inner frame can be selectively biased between raised and lowered positions while said outer frame remains at a fixed ground position; means for selectively elevating said inner frame along a vertical plane wherein said inner frame remains spaced inwardly from said outer frame such that said inner frame can be slidably guided along the vertical plane without directly contacting said outer frame; and means for supporting at least one drywall panel on top of said inner frame wherein the drywall panel can be effectively elevated between alternate heights during operating conditions while the operator's hands remain freely disengaged from the drywall panel.
 11. The lift assembly of claim 13, wherein selected ones of said inner frame support member and said selected ones of said outer frame support members are vertically oriented substantially parallel to the vertical plane and symmetrically spaced at opposing corners of said outer and inner frames respectively, other ones of said support members being horizontally oriented and medially secured to said selected support members such that said other support members become vertically aligned along a longitudinal length of said selected inner frame and outer frame support members respectively.
 12. The lift assembly of claim 14, wherein said elevating means comprises: a manually-operable jack including a rotatable winch and oppositely positioned base and top surfaces, said base surface being medially positioned on corresponding ones of said outer frame support members, said top surface being medially engaged beneath corresponding ones of said inner frame support members such that opposing lift forces will cause said inner frame to elevated when the operator adapts said jack between retracted and extended positions.
 13. The lift assembly of claim 13, wherein said elevating means further comprises: at least one rigid guide bracket having a linear central portion and an integrally coupled arcuate end portion slidably engageable with said inner frame, said guide bracket further having an opposite end portion mated with said outer frame such that said guide bracket can be maintained at a static position while said inner frame is elevated toward the ceiling.
 14. The lift assembly of claim 13, wherein said drywall panel supporting means comprises: a substantially rectangular platform sized and shaped for being positioned on an upper end portion of said inner frame, said platform having a substantially planar top surface oriented along the horizontal plane such that the drywall panel can be effectively maintained at equilibrium during transit; and a plurality of U-shaped brackets positioned about said inner frame and spaced along opposite sides thereof such that said brackets become situated subjacent said platform, each said U-shaped bracket including outwardly extending flange portions for threadably receiving fasteners therethrough such that said platform and said inner frame become securely coupled.
 15. The lift assembly of claim 14, wherein said outer frame further comprises: a plurality of elongated rails connected thereto wherein selected ones of said rails are perpendicularly oriented along traversing planes and vertically aligned along said selected outer frame support members for providing additional stability during operating conditions. 